Retaining Wall Checklist - Free Download
Thirteen practical checks to work through before you commit to a retaining wall in Perth - covering the WA permit position, engineering, drainage and getting a proper quote. Enter your email below and we'll send it to you.
Retaining Wall Perth Checklist - Method and Sources
What this is, and is not: a practical pre-project checklist, not a compliance certificate and not a substitute for council or engineering advice. What it's based on: the WA Building Act 2011 permit exemption test, AS 4678 engineering practice, and the drainage detail that most commonly causes Perth retaining wall failures - drawn from this site's own research, cited on the relevant engineered walls and drainage service pages, and from Building and Energy WA. Assumption set: a standard residential retaining wall on a typical Perth block - an unusual site or a commercial project may need checks beyond this list.
- 1
Measure the actual retained height
WA's 0.5m building-permit exemption is measured on retained ground, not wall face height - get this wrong and you may start work without a permit you actually needed.
- 2
Check boundary and proximity
A wall on or near a boundary, or within 1.5m of another structure, can need approval regardless of height.
- 3
Confirm if the wall is associated with other building work
A wall tied to a driveway, pool, extension or another structure loses the standalone-wall exemption even if it is under 0.5m.
- 4
Check for a surcharge load
Anything sitting above the retained soil (driveway, building, pool, another wall) can trigger approval at any height.
- 5
Get council confirmation in writing
WA council wording and thresholds vary in detail - a written confirmation avoids relying on a general rule that doesn't quite match your council.
- 6
Ask whether engineering is required
Structural design to AS 4678 by a registered building engineering practitioner is required once a wall crosses the relevant trigger - confirm before you commit to a design.
- 7
Check the ground condition, not just the slope
Perth's ground varies block to block - shallow limestone, loose coastal sand and clay-prone river-flat soil each need a different wall and footing approach.
- 8
Plan the drainage before the wall, not after
Ag-drain, free-draining gravel backfill and geofabric (a filter fabric that stops the drain clogging with soil) behind the wall are structural requirements, not an optional extra - retrofitting drainage later is far more expensive.
- 9
Confirm the stormwater discharge point
Drainage from a retaining wall must connect to an approved point and stay within the property boundary - it cannot be directed onto a neighbour.
- 10
Get a written, itemised quote
A quote that separates material, labour, excavation, drainage and engineering lets you compare providers properly and avoids surprise add-ons.
- 11
Ask about access and machinery reach
Hills and rear-of-block sites with limited access can add real cost - flag this before pricing, not after.
- 12
Check whether builder-contractor registration applies
Registration in WA turns on the value and nature of the job, not the wall type alone - confirm your specific project with Building and Energy WA if you're unsure.
- 13
Ask what happens with tiered or stepped walls
Some councils assess the combined height of tiered walls against the 0.5m threshold rather than each tier separately.